PTAB Invalidates Halozyme Patent Claims for Drug-Delivery Tech
In a final written decision, the Patent Trial and Appeal Board found all challenged claims of a Halozyme patent covering its PH20 enzyme technology unpatentable.
On September 1, 2026, the Patent Trial and Appeal Board (PTAB) issued a final written decision in a post-grant review finding all challenged claims of Halozyme's U.S. Patent No. 12,110,520 unpatentable. The patent covers aspects of the company's PH20 hyaluronidase enzyme technology, which facilitates the subcutaneous delivery of biologics and is used in a version of Merck’s cancer drug Keytruda.
This ruling is a significant development for pharmaceutical and biotech companies, as it could clear a path for competitors to develop and market products using similar drug-delivery systems without infringing this specific patent. For innovative drug companies, the decision underscores the vulnerability of issued patents to PTAB challenges, which have become a common tool for alleged infringers and competitors. Counsel for clients in the life sciences sector should note this outcome’s potential to alter the competitive landscape for biologic drug formulations. The next step to watch is a potential appeal of the PTAB’s decision by Halozyme to the U.S. Court of Appeals for the Federal Circuit.